Centrifuge apparatus and method



April 21, 1959 E. c. WHITEHEAD E1' AL 2,883,103

CENTRIFUGE APPARATUS AND METHOD Filed March 9. 1953 Flai ./1

l 22 l I 34 2a 28 FIG.5

BY MM* ATTORNEYS United States atet l 2,883,103 -CENTRIFUGE APPARATUS AND METHOD Edwin C. Whitehead, Crestwood, and Andrs Ferrari, Jr.,

Uniondale, N.Y., assignors to Technicon Internationai,

Ltd., Bronx, N.Y., a corporation of New York Application March 9, 1953, Serial No. 341,039 3 Claims. (Cl. 233-27) The present invention relates to centrifugal separators and, more particularly, to centrifuges for separating certain blood constituents from each other. p

A primary object of this invention is to provide a centrifuge which is capable of completely separating-one blood constituent, for example, the red cells, from another blood constituent, for example the plasma, of a given quantity of blood.

It is well known to those skilled in the art, that plasma may be infused into a donee without regard to differences in blood types but that it is `extremely dangerous to infuse red cells into a donee if his blood type does not match that of the donor. This serious danger is eliminated by the present invention.

Another object is to facilitate the return of the red cells of a blood donation to the donor.

A further object is to provide apparatus which can be easily cleaned and sterilized.

A yet further object is generally to provide an improved blood centrifuge.

The above Iand other objects, features and advantages of the present invention will be more fully understood from the following description considered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. 1 is a view of apparatus embodying the present invention, the centrifuge vessel being shown in vertical section; v

Fig. 2 is a fragmentary sectional view, on a larger scale, taken on the line 2-2 of Fig. 1;

Fig. 3 is 'a top plan View of the apparatus, on a smaller scale;

Fig. 4 is a vertical section, on a larger scale, of a portion of the centrifuge and illustrates a modification in the securement of the bottom wall to the side Wall of the vessel; and

p Fig. 5 illustrates on a smaller scale, the retaining ring utilized in the modification shown in Fig. 4.

Referring now to Figs. 1 through 3 of the drawings, which illustrate the best mode now contemplated by us for practicing the invention, the apparatus comprises a centrifuge vessel which, as here shown, is preferably in the form of a frusto-conical bowl which is provided with a dished bottom. Said vessel is removably secured to a flanged collar 12 which is keyed to the shaft 14 of a motor M for rotation thereby about a vertical axis.

The vessel 1U comprises a conical side Wall member 16 l which is in fluid-tight relation with a bottom wall member 18 which is provided with the central dished portion or well 20. The outer surface 22 of the bottom wall extends downwardly yand is inclined outwardly from the perimeter 23 of the well and terminates in a circular flange 24. Said llange is seated in la complementary shoulder 26 defined in the bottom rim 28 of the member 16, being secured `ilange 24 of the `bottom wall member 18 to form the bottom of the trough 32. The screws 30 secure the ange thereto in duid-tight relation, as by the screws 30. It i ice 27 and the underlying portion of the bottom wall in fluidtight relation. It will also be noted that the trough is open at the'upper end thereof, at the perimeter 23 of the dished portion 20. A plurality of equally spaced fins or vanes 34 are carried by the Wall member 16 and extend into the trough 32 and also have a portion 36 which extends into the well 20, as best illustrated. in Fig. l. It will be noted that the ns 34 are spaced from the bottom wall surface 22 so that the chambers in the trough 32, which are dened by said iins, are in uid communication with each other through said spaces. The wall member 16 converges toward the vertical axis of rotation `and iS provided with an upper rim 38 for receiving a suitable cover (not shown), which may be `releasably secured thereto. It will be observed that the inner wall of trough 32 forms a dam between the two compartments.

In order to removably mount the vessel 10 for rotation about a vertical axis by the motor shaft 14, the bottom wall member 18 is provided with `a central recess 4i) for receiving an apertured hub member 42. The hub is pro vided with a circular flange 44 and a plurality of bolts 46 extend through the ange into the bottom wall to secure the latter together. The hub 42 is provided also with a pair of locating pins 48 for insertion into the bottom wall member 1S to eect correct alignment of said parts. The tapered collar 12 is keyed to the motor shaft 14 by the cross pin 50. The collar is provided with a circular ange S2 and with thepair of upstanding locating pins 54. A locking nut 56 seats under the collar liange 52, as best illustrated in Fig. l, and is internally threaded for threaded engagement with the hub 42, the latter being provided with 'apertures 58 for receiving the locating pins 54. From the foregoing, it will be readily apparent that with the hub 42 secured to the bottom wall 18, and with the collar 12 keyed to the motor shaft 14, the apparatus -may be readily assembled for rotation Iby the motor M, by seating the hub on the shaft Icollar with the locating pins 54 on the collar extending into the `apertures 58 in the hub. Thereafter, the locking nut 56 locks the hub to the shaft collar. The vessel 10 may lbe readily removed from the motor M by merely retracting the locking nut out of engagement with the hub, whereby the vessel may be conveniently removed, With the hub thereon, from the motor.

Referring now to the modification illustrated by Figs. 4 and 5, the previously mentioned securing screws 30 are eliminated and in place thereof a huid-tight engagement between overlying portions of side wall 16A and bottom wall 18A of the vessel is obtained by means of the resilient snap ring 60. It will be noted that the ring 60 is provided with a plurality of concave or inwardly directed arcuate portions 62. Pursuant to the present modification, the bottom rim 28A of the side wall member 16A is extended beyond the bottom Wall 18A.4 Said rim `28A is provided with the circular recess or seat 64, for the spring ring 60. It will be noted that the bottom wall is provided with a slight bevel, as at 66, at the outer edge thereof adjacent the recess 64. Said bevel extends into the path of movement of the spring when it snaps into the` seat so that the spring ring presses against said bevelled portion to provide for a tight. liquid seal between the parts. During the rotation of the vessel 10, and as the centrifugal force increases, the diameter of the ring 6i) ltends to increase at the arcuate portions 62 thereof, which move outwardly against the bevelled portion 66 so that an increased force is exerted upwardly against the bevelled surface, to tighten the liquid seal. The blood donation may be taken from the patient and deposited in the vessel 10 in any suitable manner, for example, as described in the patent to Aronson, No. ln the usual quantity of blood, ordinarily about 500 cc., .which is talcen from the donor and re- 20 of the bowl.

ceived in the vessel 10, there will be approximately 250 cc. of red cells. Accordingly for a donation of this amount, the trough 32 is designed to have a capacity somewhat larger than 250 cc; so` that after the operation of the centrifuge is completed all ofthe red cells will be in trough 3,2 and thus completely separated from the plasma most of which will be disposed, externally Vof the trough, in the dish portion 20 of the bowl.

With the donated blood contained in lthe vessel the latter is secured to the collar 12, as previously described, and the vessel is then rotated at a suitable high speed. Said speed may be approximately 7,000 r.p.m., to centrifuge the blood vin the vessel. Due to the centrifugal action, the plasma and the red cells separate during the'rotation of the vessel 10.. However, since the red cell component is heavier than the plasma component, the formeris subjected to a greater centrifugal Vforce than the vlatterand therefore the inclined wall 16 applies a greater downward'force to the red cells than to the plasma so that the trough lls up substarr tiallyv with the red cell component which therefore causes the plasma to flow outiof the trough into part Thus, when the rotation of the vessel is stopped, the red cells and the plasma are maintained segregated from each other in separated parts, respectively, of the bowl. As previously indicated, the trough is designed to have a capacity such that it is almost completely filled by the heavier red cell component so that the lighter plasma, which cannot be accommodated in the trough, flows into and is retained in the portion 20 at the termination of the rotation of the vessel 10 and there will be no red cell in the plasma. Therefore, substantially the total amount of douce-available plasma, for a stated donation of blood, is greatly increased and since the plasma is devoid of red cells the danger to a donee of a different blood type is obviated. It will be understood that the ns 34 cause the blood in the vessel 10 to rotate therewith and thus improve the centrifugal action ,for separating the plasma from the red cells in vessel 10 inthe centrifuging operation. As previously indicated, said ns are spaced from the surface 22 of the bottom wall 15 so that all of the red cells which are contained in the trough may be readily removed therefrom for reinfusion in the donor, if desired. lIn this connection, it will be understood that the plasma may be removed from kthe portion 20 and the red cells removed from the trough 32 by suitable apparatus, for example as illustrated and described in the above mentioned patent. However, it is understood that any other suitable means may be utilized to separately withdraw the plasma and the red cells after the centrifugingaction has been completed. It will be observed that since the red cells are entirely separated from the plasma and disposed in separated compartments of the centrifuge bowls, there is no danger of the red cells mixing with the douce-available plasma.

The inner surfaces of the vessel 10 are preferably coated with polytetrafluoroethylene, which is sold under the trade name of Teflon, or with other suitable antiwetting material.

While 'the operation of the centrifuge vessel 10 has been described in connection with the separation of the red cells from the plasma in whole blood, it will be understood that it is within the scope of the present invention to utilize the centrifuge vessel 10 for other purposes, for example to separate plasma into serum albumin and gamma globulin.

While I have shown and described the preferred embodiment of my invention, it will be understood that various changes may be made without departing from thelunderlying idea or principles of the invention within the scope of the appended claims.

Having thus described our invention, what We claim and desire to secure by Letters Patent is:

1. A centrifuge for separating the plasma and red cells of blood into segregated'constituentvoluinea comprising a vessel rotatable about a vertical axis to perform a centrifuging operaticlrn` and having defined at the bottom thereof a central well Vand a trough disposed radially outwardly thereof, said well having an outer periphery delining the inner side wall of said trough, said trough having an open upper end at the periphery of the well and the latter being inclined downwardly from its periphery to the axis of rotation, whereby, with said trough having a capacity not less than the separate constituent red cell volume in a predetermined volume of blood received in said vessel for centrifug'ing but lessv than said predetermined volume of blood, said trough, upon completion of the centrifuging operation, will con-tain all of the said separate'constituent red cell volume of said predetermined volume of blood, said vessel having a bottom lwall provided with saidr"wel1I and an outer side wall extending upwardly therefrom, saidfouter side wall being conical and converging v upwardly from said bottom wall `and forming the outerA wal-l of said trough, said `inner side wall ofthe trough converging upwardly from said bottom and the upper surface of said ,i well being dish-shaped and terminating at the top of said inner side wall of said trough, said outer side Wall of the trough extending upwardly beyond the top of said inner wall. Y

2. A centrtifuge for separating the plasma and red cells of the bloody into segregated constituent volumes, comprising a frustoc`on`ical bowl rotatable about a vertical axis, said bowl having means defining an annular trough convergingupwardly from the bottom thereof and a centrally dished portion disposed radially inwardly of the trough and having a concave upper surface extending to the upper open end thereof, said 'trough having a capacity not less than the separate constituent red cell volume inV a predetermined volume of blood received in said vessel forcentrifuging but less than said prede- Itermined volume of blood, whereby after the centrifuging operation is completed, ysaid trough 'will contain said separate constituent red cell volume and said dished portion will contain plasma free of red cells.

3. A` centrifugeA vessel for separating the plasma and red cells'of blood intovsegregated constituentvolumes, said vessel comprising alV frusto-conical bowl rotatable about a vertical axis, said bowl having meansA dening an annular troughconverging upwardly from the bottom thereof and a centrally dishedportion disposedv inwardly of the trough andextending to the upper open end thereof, said trough havingV afcapacity not less than the separate constituent red cellvolume inca predetermined volume of blood received in saidvessel for centrifuging, but less than said predetermined Volume of blood, whereby after completion of the centrifuging operation, said trough will contain all of said separate constituent red cell volume and s aid dished portion will contain plasma free of red cells, and applurality of spaced'vanes having portionsl extending into and'termivnating above the bottom of said trough.

References Cited in the leof this patent UNITED STATES PATENTS 

